This invention relates to an electrostatic air cleaning device, and more particularly to a plug-in power module for an electrostatic air cleaner device.
Electrostatic precipitators of air cleaning devices are well known in the art. Such devices usually include 2 stages for treating the air, a first ionizing stage and a second collector stage. In the ionizing stage, the air moves past one or more ionizing wires from which are spaced grounded electrodes to provide an electrostatic field in which the particles in the air are ionized or electrically charged. The ionized particles then move through the second collector stage, which constitutes a plurality of alternately charged and grounded parallel collector plates creating electric fields. The ionized particles are attracted to one collector plate or the other, depending upon the charge on the particle. The air then leaves the second stage, minus the particles, in a cleaner and more purified state.
In the U.S. Pat. No. 4,007,024 for "PORTABLE ELECTROSTATIC AIR CLEANER" issued Feb. 8, 1977 to John P. Sallee, et al, and owned by the Assignee of the instant invention, the electrostatic air cleaner is made in the form of a relatively thin cell to permit the cell to be interchangeable with standard mechanical air filters positioned transversely in an air duct. The ionizing wires and the collector plates are arranged in substantially the same transverse plane, and the collector plates are disposed at an angle to the flow path in order to increase the effective flow path through the filter cell. Thus, with an electrostatic air cleaner cell as taught by the above Sallee et al patent, no separate installation operation is required. It is only required to withdraw the existing mechanical air filter transversely along its tracks from within the air duct, and to insert the thin electrostatic air cell along the same tracks to extend across the air passage within the duct.
The power supply for electrostatic air cleaners heretofore known, including the thin air cleaner disclosed in the Sallee et al U.S. Pat. No. 4,007,024, is in the form of a relatively large power pack including electrical circuitry and components, such as a relatively large transformer, a rectifier and an oscillator circuit. The function of the power pack is to convert standard household AC voltage, such as 110-120 VAC, into direct current voltage of substantially greater values, such as 5-7 kilovolts, sufficient to create the necessary electrostatic field around the ionizing wires to precipitate the solid particles carried by the air stream through the filter cell. Such power packs must be installed by qualified personnel, such as electricians. An output cable from the power pack is connected to the air filter cell, while a separate cable connected to the AC input circuit within the power pack must be wired into the electrical system within the building in which the air filter is installed.
Examples of such electrical power packs are disclosed in the following U.S. patents:
______________________________________ 1,992,974 Thompson Mar. 5, 1935 2,933,151 Kurtz Apr. 19, 1960 3,108,865 Berly Oct. 29, 1963 3,800,509 Carr et al Apr. 2, 1974 4,007,024 Sallee et al Feb. 8, 1977 ______________________________________